JPH029258B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electric water heater.

Conventional configuration and its problems Figure 1 shows a conventional instantaneous electric water heater, which is used, for example, in showers.

In FIG. 1, water flowing in from an inlet 1 passes through a valve 2 and an inlet pipe 3, enters a container 4, flows around two sheathed heaters 5 and 6, and is heated.
It flows out from the shower head 8 via the outlet pipe 7. 9 is a pressure switch which closes the electric circuit when the water pressure reaches a predetermined pressure. Numeral 10 is a switch that changes the state of energization to the two sheathed heaters 5 and 6. The wattage, or calorific value, is selected mainly based on the water temperature on the inlet side, and the flow rate is adjusted using the valve 2 to obtain hot water at an appropriate temperature.

The first problem with the conventional example is that the flow of water flowing into the container 4 from the inlet pipe 3 attached to the bottom of the container 4 uniformly contacts the entire surface of the sheathed heaters 5 and 6 as shown by the arrow. Instead, most of it rises up the center of the spirally wound sheathed heater 5, hits the upper part of the container 4, and flows out from the outlet pipe 7. Therefore, especially in the lower part of the sheathed heater 6, the flow rate of water is slow, so heat transfer is poor.
The temperature of the sheathed heater will rise and it will boil locally, and if used for a long time, magnesium compounds and calcium compounds (hereinafter referred to as scale) in the water will accumulate, which will worsen heat transfer and cause the sheathed heater to break. I was getting used to it.

The second problem with the conventional example is that it takes a long time from the start of use until the water temperature rises and reaches the saturation temperature (hereinafter referred to as rise time). This is because, as stated in the explanation of the first problem, since the flow of water is undesirable, a portion of the interior of the container 4 is heated more than necessary and heat is accumulated.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to provide an electric water heater that has a short start-up time and does not have a sheathed heater disconnected even after long-term use.

Structure of the Invention In order to achieve the above object, the electric water heater of the present invention has the following features:
Two sheathed heaters wound spirally on one side and the other are housed in a container, and a divider is formed between the two sheathed heaters to form a main conduction part at the bottom and a sub-conduction part at the top. An inlet pipe whose open part is located in the center of the first sheathed heater is located near the upper end of the container, and an outlet pipe whose open part is located in the center of the second sheathed heater near the upper end of the container. The water flowing in from the inlet pipe flows into the first pipe from the open part at the upper end.
It descends near the helical part of the second sheathed heater, passes through the lower conducting part of the dividing plate, ascends near the helical part of the second sheathed heater, and flows out through the inside of the outlet pipe from the open upper end of the outlet pipe. At the same time, a part of the water flowing in from the inlet pipe is configured to flow from the upper end open part of the outlet pipe through the upper sub-conducting part of the dividing plate, and from the upper end open part of the outlet pipe through the inside of the outlet pipe. It is something.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 1 is a water inlet, and 2 is a valve that can open and close the water and adjust the flow rate. Reference numeral 11 denotes an inlet pipe that passes through the bottom of the container 4, and has an open portion 11a located near the upper end of the container. 5 is the first spirally wound
This sheathed heater is disposed substantially concentrically with the inlet pipe 11 and is soldered to the upper end of the container 4. 6 is a second sheathed heater spirally wound;
It is arranged substantially concentrically with the outlet pipe 7 and is soldered to the upper end of the container 4. The opening 7a of the outlet pipe 7 is located near the upper end of the container 4, and the shower head 8 is connected to the lower end by a hose.

A dividing plate 12 divides the container 4 into two, forming a lower main communication section 13 and an upper sub-conduction section. Reference numeral 10 is a Watt changeover switch, and reference numeral 9 is a pressure switch, which are wired to power terminals L and N as shown in the figure.

The operation of the above configuration will be explained below.
When valve 2 is opened, water flows from inlet 1 to inlet pipe 11
, and flows out into the container 4 from the upper end opening 11a. Most of the water flowing into the container 4 is absorbed by the dividing plate 12.
The main communication portion 13 is formed at the lower part of the dividing plate 12 and collides with or descends along the spiral portion of the first sheathed heater 5 between the outer wall formed by the right half of the container 4 and the inlet pipe 11 . It enters the left half of the container 4 through the passageway, collides with or rises along the spiral part of the second sheathed heater 6, reaches the upper part of the container 4, and flows into the outlet pipe 7 through the upper end opening 7a of the outlet pipe 7. The water flows out from the shower head 8.

On the other hand, a part of the water flowing into the container 4 from the inlet pipe 11 enters the left half of the container 4 through the sub-conducting part 14 formed at the upper part of the dividing plate 12, and enters the left half of the container 4 through the upper open part 7a of the outlet pipe 7. The water flows into the outlet pipe 7, merges with the water flow rising from below the second sheathed heater 6, and flows into the shower head 8.
More leakage.

A pressure switch 9 is attached to the inlet pipe 11 and closes the electric circuit when the water pressure reaches a predetermined pressure. The Watts changeover switch 10 connects the two sheathed heaters 5,
6, the power supply state to the first sheathed heater 5 only.
ON, only the second sheathed heater 6 is ON, or the two sheathed heaters 5 and 6 are switched ON at the same time. Then, switch 10
By adjusting the valve 2 and the valve 2, the appropriate temperature of the shower can be obtained.

FIG. 3 shows a partial detailed view of the sub-conducting portion 12. FIG. 3a is a side view of the container 4, the dividing plate 12, and the sub-conducting part 14 of the embodiment of the present invention shown in FIG. It is formed by cutting out the top.

Figures 3b and 3c show other embodiments, b is the dividing plate 1
4 by cutting out both upper corners to form a sub-conducting part 14,
c is formed by providing a recess in the top of the container 4. Types a and b have the advantage of simple structure and processing, and type c has the advantage of good air release.

According to this embodiment, the water flow uniformly contacts the entire surfaces of the two sheathed heaters 5, 6, generates a turbulent flow at high speed, and improves heat transfer between the sheathed heaters 5, 6 and the water. is carried out effectively. Further, by means of the sub-conducting portion 4 provided at the upper part of the container 4, the air accumulated in the upper right side of the container 4 is discharged to the left side of the container 4, and is mixed with hot water and discharged from the outlet pipe 7.

In other words, on the right side of the container 4, the descending water flow is slow, making it difficult to mix air and drain water, but on the left side of the container 4, the flow rate of the outlet pipe 7 is extremely fast, making it possible to discharge air. The sub-conducting portion 14 utilizes the following.

Further, when the valve 2 is closed, the sub-conducting portion 14 allows the hot water on the left side of the container 4, which has a relatively high temperature, and the hot water on the right side of the container 4, which has a relatively low temperature, to combine with the lower main communication portion 13 of the container 4. Acts like a natural cycle,
Mixing prevents hot water from coming out the next time. As a result, firstly, the sheathed heater 5,
The surface temperature of the sheathed heaters 5 and 6 is kept low, local boiling does not occur, and disconnection of the sheathed heaters 5 and 6 due to scale adhesion does not occur. Short rise time, 3rd
This has the effect that the rise in temperature of the hot water in the container 4 (post-boiling) due to the heat capacity of the sheathed heaters 5 and 6 after the valve 2 is closed is small.

Effect of the invention According to the present invention, the following effects can be obtained.

(1) The surface temperature of the sheathed heater is kept low and uniform, local boiling does not occur, and disconnection of the sheathed heater due to scale adhesion does not occur.

(2) Heat transfer between the sheathed heater and the water is good, and the time from when hot water starts to when hot water at the appropriate temperature is obtained is short.

(3) The temperature of the sheathed heater is kept low and uniform,
In addition, the hot water on the left and right sides of the container is mixed by natural circulation after the valve is closed, and there is little backflow due to the heat capacity of the sheathed heater.

(4) The air inside the container is quickly exhausted.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional electric water heater, Fig. 2 is a block diagram of an electric water boiler according to an embodiment of the present invention, and Fig.
Figure a is a partially detailed view showing the sub-conducting part 12 in one embodiment of the present invention shown in Fig. 2, and Figures 3 b and c are partially detailed views showing the sub-conducting part and another embodiment of the present invention. be. 4... Container, 5... First sheathed heater, 6...
...Second sheathed heater, 7...Outlet pipe, 7a
...Opening part of the outlet pipe, 11...Inlet pipe,
11a... Opening part of the inlet pipe, 12... Division plate, 13... Main conducting part, 14... Sub-conducting part.

Claims (1)

[Scope of Claims] 1. A container that stores first and second spirally wound sheathed heaters on one side and the other side thereof and generates hot water using the heat thereof, and the first and second sheathed heaters. a dividing plate that is located in between and forms a main conduction part in the lower part of the container and a sub-conductor part in the upper part of the container; and a partition plate that is located approximately at the center of the first sheathed heater and opens near the upper end of the container. an inlet pipe in which a portion is located, and an outlet pipe in which an open portion is located approximately in the center of the second sheathed heater and near an upper end inside the container, and water flowing from the inlet pipe is provided at the upper end open portion. descending near the helical part of the first sheathed heater,
The water rises near the spiral part of the second sheathed heater through the lower main communication part of the dividing plate, flows out from the upper end open part of the outlet pipe through the inside of the outlet pipe, and flows in from the inlet pipe. The electric water heater is configured such that a part of the water flows out from the upper end open part of the outlet pipe through the upper sub-conducting part of the dividing plate and from the upper end open part of the outlet pipe through the inside of the outlet pipe. 2. The electric water heater according to claim 1, wherein the sub-conducting portion is formed by providing a notch in the splitting plate. 3. The electric water heater according to claim 1, wherein the sub-conducting portion is formed by providing a recess in the top of the container.